The question is asking us to understand how the variables X and Y are related at any given time, as shown in Fig. (i), and to figure out how Y varies over time, based on the given periodic variation of X over time in Fig. (ii).

Option 1: This cannot be our choice because it shows a constant Y value over time which is not in line with the described relation.

Option 2: This might be tempting but it incorrectly predicts a symmetrical change in Y`s value over time, which would imply X and Y are directly proportional, which is not given.

Option 3: This is the correct option because it accurately represents how a change in X`s value influences Y`s value over time, acknowledging the relationship shown in Fig. (i). As X periodically increases and decreases, Y correspondingly oscillates around a particular value, but not symmetrically.

Option 4: This shows an inversely proportional relationship between Y and X, which doesn`t align with the described relationship between the two variables.

So, knowing the relationship between X and Y, along with X`s variation over time, allows us to predict the variation of Y over time, leading us to correctly choose option 3.