Answer:
Option d -

Explanation:
Given : Event B is dependent on event A, and event A occurs before event B.
To find : Which formula can be used to find the probability of event A?
Solution :
Event B is dependent on event A
i.e. The intersection of A and B - A and B
Probability of event B is dependent on event A is P(A and B)
Event A occurs before event B
i.e. B|A
Probability of event A occurs before event B is P(B|A)
Event B is dependent on event A, and event A occurs before event B is

The formula which shows the probability of event A is

Therefore, Option d is correct.