Which one of the following examples represents a repeating decimal a. 1.4 b. 0. c. 4.252525 d. 0.123123

Actually, i think something is missing here:

You need either a parenthesis or some dots at the end to determine this. A repeating decimal can have one repreating digit:

0.(7): 0.777777...

two:

0.(45): 0.45454545454545

or more: so potentially all of them can be repeating, even a!

it could be: 1.(111114)

or: 1.111114111114111114111114111114111114111114111114111114111114111114111114111114...

proably B. is the most typical of repeating decimals (choosed this one if you have to), but in reality, you need more information... did you copy the question exactly?