The element that shows greater ability to form $$p\pi - p\pi$$ multiple bonds is:

First, let us list the four elements once again: C (carbon), Si (silicon), Ge (germanium), Sn (tin). All of them belong to Group 14 of the periodic table and each possesses the general outer-shell configuration $$ns^2np^2.$$

Now, the ability to create a $$p\pi - p\pi$$ multiple bond (for example $$C=C$$ or $$C{\#}C$$) depends mainly on two related factors: the effective sideways (lateral) overlap between two $$p$$ orbitals, and the matching in energy of those $$p$$ orbitals. For good overlap, the orbitals must be (i) sufficiently small and (ii) held close to the nucleus so that their lobes meet accurately in space.

Moving down the group from $$\text{C}$$ to $$\text{Sn},$$ we have an increase in principal quantum number $$n$$: the $$p$$ orbitals change successively from $$2p$$ to $$3p$$ to $$4p$$ to $$5p.$$ A higher $$n$$ means:

$$\text{Larger orbital radius} \;\; \Longrightarrow \;\; \text{more diffuse lobes}.$$

Diffuse lobes overlap less efficiently sideways, making the formation of strong $$p\pi - p\pi$$ bonds increasingly difficult. Therefore the multiple-bond strength trend strictly decreases as we descend the group.

We can reinforce this idea by recalling observed chemistry:

$$\begin{aligned} \text{C} &\;\; \text{readily forms}\; C=C,\; C{\#}C,\; C=O,\; C=N, \text{etc.} \\ \text{Si} &\;\; \text{rarely forms}\; Si=Si\; (\text{few compounds exist}). \\ \text{Ge} &\;\; \text{forms Ge=Ge only under special conditions}. \\ \text{Sn} &\;\; \text{virtually never shows Sn=Sn double bonds in simple molecules}. \\ \end{aligned}$$

Hence, among the four, carbon’s $$2p$$ orbitals provide by far the best lateral overlap, giving it the greatest propensity toward multiple bonding via $$p\pi - p\pi$$ interaction.

Thus the order of ability is

$$\text{C} \gt \text{Si} \gt \text{Ge} \gt \text{Sn}.$$

Since the question asks for the element that shows greater ability (i.e., the greatest among those listed), the choice must be carbon.

Hence, the correct answer is Option B.