Many people overestimate how long they actually remain awake during restless nights because their moments of wakefulness are easier to recall than their moments of sleep. this best illustrates the impact of select one:

a. the availability heuristic.
b. framing.
c. confirmation bias.
d. a critical period.

   A. The availability heuristic

Explanation: For heuristic availability, examples that come to mind are crucial. Heuristic availability, by definition, is, in fact, a mental shortcut by which particular examples come to mind first when a particular event or reflection on a topic. So those examples that come to mind first are crucial in evaluating a particular topic or event because they first came up as an option and came to mind with a mental shortcut. This does not mean that other options do not exist, they just do not come to mind. So the people who first think of the moments when they are awake during the sleepless nights and overestimate that fact and will ignore the fact that they still slept during those nights.

i think it is the third one.