If a cell A with OP 10 bars and TP 4 bars is connected to cells, B, C and D having OP and TP respectively 4 and 4, 10 and 5 and 7 and 3 bars, the flow of water will be

Options

A. C to A, B and D
B. B to A, C and D
C. A to D, B and C
D. A to B, C and D

Answer

To solve the problem of water flow between the cells A, B, C, and D based on their osmotic pressure (OP) and total pressure (TP), we will follow these steps:

### Step 1: Calculate the Diffusion Pressure Deficit (DPD) for each cell.
The formula for DPD is:
\[ \text{DPD} = \text{OP} - \text{TP} \]

1. For Cell A:
- OP = 10 bars
- TP = 4 bars
- DPD_A = 10 - 4 = 6 bars

2. For Cell B:
- OP = 4 bars
- TP = 4 bars
- DPD_B = 4 - 4 = 0 bars

3. For Cell C:
- OP = 10 bars
- TP = 5 bars
- DPD_C = 10 - 5 = 5 bars

4. For Cell D:
- OP = 7 bars
- TP = 3 bars
- DPD_D = 7 - 3 = 4 bars

### Step 2: Compare the DPD values.
- DPD_A = 6 bars
- DPD_B = 0 bars
- DPD_C = 5 bars
- DPD_D = 4 bars

### Step 3: Determine the direction of water flow.
Water moves from areas of lower DPD to areas of higher DPD.

- The lowest DPD is in Cell B (0 bars).
- The highest DPD is in Cell A (6 bars).

### Step 4: Identify the flow of water.
Since water moves from lower DPD to higher DPD:
- Water will flow from Cell B (0) to Cell A (6).
- After reaching Cell A, water can also flow to Cells C (5) and D (4) since they have higher DPD than Cell B.

### Conclusion:
The flow of water will be from Cell B to Cell A, and then it can also go to Cells C and D.

### Final Answer:
The correct option is: **B to A, C, and D.**

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