1.A questionnaire on accounting software usage was sent to a sample of small businesses. Of the 250 responses received, 150 indicated that their business currently used accounting software. 50 of the total replies received were completed by clerical staff, of whom 30 also indicated that the firm used that software.

What is the probability that any particular questionnaire returned was from a business using that software and was filled in by non-clerical staff?

A.0.12

B.0.4

C.0.48

D.0.6