Match the following.

List-I (Variances)	List-II (Causes)
a. Overhead efficiency variance	1. Power failure
b. Overhead volume variance	2. Appointing low grade employees
c. Labour idle time variance	3. Poor working condition
d. Labour efficiency variance	4. Working days being more or less than budgeted

A. a-4, b-3, c-2, d-1

B. a-3, b-4, c-1, d-2

C. a-3, b-1, c-4, d-2

D. a-2, b-1, c-4, d-3

Answer: Option B