Find the missing number in the following series :
शृंखला में लुप्त संख्या ज्ञात कीजिए।
43, 172, 86, 344,?

Options

A. A)172
B. B)258
C. C)129
D. D)430

Explanation

To find the missing number in the series: 43, 172, 86, 344, ?, we can analyze the pattern of the numbers given.

### Step-by-Step Solution:

1. **Identify the Pattern**:
- The first number is 43.
- The second number is 172, which is 43 multiplied by 4.
\[ 43 \times 4 = 172 \]

2. **Next Number**:
- The third number is 86, which is 172 divided by 2.
\[ 172 \div 2 = 86 \]

3. **Following Number**:
- The fourth number is 344, which is 86 multiplied by 4.
\[ 86 \times 4 = 344 \]

4. **Finding the Missing Number**:
- To find the fifth term, we take the fourth term (344) and divide it by 2.
\[ 344 \div 2 = 172 \]

Thus, the missing number in the series is **172**.

### Final Answer:
The missing number is **172**.