Using the concept of independent events, it is found that the correct statement is:
a and b are independent events because p(a∣b) = p(a) = 0.75.
<h3>When are two events independent?</h3>
Two events, A and B, are independent if:

In this problem, the events are:
In this problem, out of 300 students, 225 have surfed, hence:

48 have gone snowboarding, hence:

36 have done both, hence:

The multiplication is:
P(A)P(B) = 0.75 x 0.16 = 0.12.
That is, the probability of A given B is P(A|B) = P(A) = 0.75, hence they are independent.
More can be learned about independent events at brainly.com/question/14478923