Answer:
C. Children have much greater chance of having side effects than adults.
Explanation:
It is known that the conditional probability for two events A and B is given by,
.
Then, according to the table, we have,

i.e.

i.e.

Moreover,

i.e.

i.e.

As 0.40 > 0.12.
Children have more chances of having side effects than adults.
Hence, option C is correct.