If a radiographic image was obtained with a 1/4 (one quarter) second exposure time, which of the following should be selected if a repeat exposure requires double the exposure time?

exposure time would be 1/2 second

Explanation: doubling the exposure time means you would take 1/4 x 2 which is 1/2

out of the choices i'd say d the ability to set goals, mainly because to desire to continue you need motivation but it isn't motivation in that part, but setting goals means you have an endgame and you want to reach it which sums up motivation.