Which statement is correct ?
(a) The cardiac output of an athelete is higher than an ordinary man.
(b) The body has the ability to alter the stroke volume as well as the heart rate.
(c) The stroke volume multiplied by the heart rate gives the cardiac output

Options

A. a and b
B. a, b and c
C. b and c
D. b and c

Answer

To determine which statement is correct regarding cardiac output, let's analyze each option step by step.

### Step 1: Understanding Cardiac Output
Cardiac output (CO) is defined as the volume of blood the heart pumps per minute. It is calculated using the formula:

\[ \text{Cardiac Output (CO)} = \text{Stroke Volume (SV)} \times \text{Heart Rate (HR)} \]

### Step 2: Analyzing Each Statement
1. **Statement (a)**: "The cardiac output of an athlete is higher than an ordinary man."
- **Analysis**: Athletes typically have a higher cardiac output due to their increased physical activity and conditioning. Their hearts are more efficient, allowing them to pump more blood per beat (higher stroke volume) and often have a higher heart rate during exercise. Thus, this statement is **correct**.

2. **Statement (b)**: "The body has the ability to alter the stroke volume as well as the heart rate."
- **Analysis**: The body can indeed adjust both stroke volume and heart rate in response to various factors such as exercise, stress, and overall health. This adaptability is crucial for maintaining adequate blood flow during different activities. Therefore, this statement is also **correct**.

3. **Statement (c)**: "The stroke volume multiplied by the heart rate gives the cardiac output."
- **Analysis**: This is a direct restatement of the formula for cardiac output. Since CO is calculated by multiplying stroke volume by heart rate, this statement is **correct**.

### Conclusion
All three statements (a), (b), and (c) are correct.

### Final Answer
The correct statements are:
- (a) The cardiac output of an athlete is higher than an ordinary man.
- (b) The body has the ability to alter the stroke volume as well as the heart rate.
- (c) The stroke volume multiplied by the heart rate gives the cardiac output.