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, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Evaluate Statement (a)**: "The cardiac output of an athlete is higher than an ordinary man."
- Cardiac output (CO) is defined as the amount of blood the heart pumps in one minute. Athletes typically have a higher cardiac output due to their training and physical conditioning, which allows their hearts to pump more blood efficiently during exercise. Therefore, this statement is **correct**.

2. **Evaluate Statement (b)**: "The body has the ability to alter the stroke volume as well as the heart rate."
- Stroke volume (SV) is the amount of blood pumped by the heart with each beat, and heart rate (HR) is the number of beats per minute. The body can indeed adjust both stroke volume and heart rate in response to various factors such as exercise, stress, and overall physical condition. This statement is also **correct**.

3. **Evaluate Statement (c)**: "The stroke volume multiplied by the heart rate gives the cardiac output."
- The formula for cardiac output is given by:
\[ \text{Cardiac Output (CO)} = \text{Stroke Volume (SV)} \times \text{Heart Rate (HR)} \]
- This statement accurately describes the relationship between stroke volume, heart rate, and cardiac output. Thus, this statement is **correct** as well.

### Conclusion:
All three statements (a), (b), and (c) are correct. However, the question asks for which statement is correct, and since all statements are indeed correct, we can conclude that the correct answer includes all options.