A

To determine the necessary connection for seven capacitors each of capacity C to achieve a total capacitance of C/3, we consider the following steps:

1. **Understanding Capacitor Configuration:** The total capacitance of capacitors connected in series is given by:
\[ \frac{1}{C_{total}} = \frac{1}{C_1} + \frac{1}{C_2} + ... + \frac{1}{C_n} \]
For two capacitors of capacity C in series, the total capacitance is:
\[ C_{total} = \frac{C}{2} \].

2. **Analyzing Total Capacitance Requirement:** We need to achieve a total capacitance of \( C/3 \). To obtain this capacitance using series and parallel combinations, we can connect a certain number of capacitors in series, then connect these sets in parallel.

3. **Creating Combinations:** For every 2 capacitors in series, we get \( \frac{C}{2} \). If we take 3 such pairs (6 capacitors), we can get three capacitors of value \( \frac{C}{2} \) in series. The total of these will be:
\[ C_{total} = \frac{\frac{C}{2}}{3} = \frac{C}{6} \]. We still have one capacitor left which can be connected in series to gain additional capacity.

4. **Placement:** Hence, if we connect two sets of three capacitors in parallel, plus one capacitor in series with them, we can achieve the overall capacitance of \( C/3 \).

5. **Final Configuration:** Referring to the provided figures for confirmation, the configuration represented in Option A meets these requirements. Hence, Option A is the correct connection to achieve the desired capacitance.

Therefore, the correct answer is A.