What is the response in the following situation? Over several weeks, a tomato plant grows towards the window with the sunlight shining through

Question

$\begin{array}{1 1} (a)\; \text{there isn't a response in the situation} \\ (b)\; \text{several weeks} \\ (c)\; \text{tomato plant growing} \\ (d)\; \text{window with sunlight} \end{array}$