Assume that the customer master file and the transaction file consist of the record numbers shown in the following sequence: Master file 3, 7, 23, 76, 79, 99 Transaction file 3, 4, 23, 23, 7, 76, 99 The record number 99 denotes the logical end of the file. The program processes records in ascending order.

Required: Indicate the master records which were not updated.

Select one or more:

a. 3

b. 7

c. 23

d. 76

e. 79