A ……..regulators are able to maintain homeostasis by means which enesures constant body temperature constant osmotic concentration, etc. All ……B……..and …………C…………and a very few lower vertabrate and invertebrate species are indeed capable of such regulation (thermoregulation and osmoregulation). Evolutionary biologists believe that the success of mammals is largely due to their ability tomaintain a constant body.........D.........and thrive wheather they live in Antarctica or in the sahara desert
Choose the correct option for A,B,C and D .

Options

A. A-Behavioural, B-vertebrates, C-invertebrates, D-temperature
B. A-Behavioural, B-bird, C-mammals,D-temperature
C. A-physiological, B-bird,C-mammals, D-temperature
D. A-behavioural, B-vertebrates, C-invertebrates

Answer

To solve the question, we need to fill in the blanks A, B, C, and D with the most appropriate terms based on the context provided. Let's go through each blank step by step.

### Step-by-Step Solution:

1. **Identify the first blank (A)**:
- The sentence states: "A …….. regulators are able to maintain homeostasis by means which ensures constant body temperature, constant osmotic concentration, etc."
- Here, we are looking for a type of regulator that maintains homeostasis. The options presented are likely to include terms like "physiological," "behavioral," etc.
- **Conclusion**: The correct term is "physiological" because physiological regulators are known to maintain homeostasis effectively.

2. **Identify the second blank (B)**:
- The sentence continues: "All ……B……..and …………C…………and a very few lower vertebrate and invertebrate species are indeed capable of such regulation (thermoregulation and osmoregulation)."
- We need to fill in two types of organisms. The options likely include "birds," "mammals," "vertebrates," and "invertebrates."
- **Conclusion**: The correct terms are "birds" for B and "mammals" for C, as both are known to have the ability to regulate their internal environment.

3. **Identify the fourth blank (D)**:
- The sentence concludes: "Evolutionary biologists believe that the success of mammals is largely due to their ability to maintain a constant body.........D.........and thrive whether they live in Antarctica or in the Sahara desert."
- The context suggests we are looking for a term that describes a constant internal condition that supports survival in various environments.
- **Conclusion**: The appropriate term is "temperature," as it directly relates to the ability of mammals to maintain homeostasis.

### Final Answers:
- A: Physiological
- B: Birds
- C: Mammals
- D: Temperature