Terror management theory

We discussed terror management theory and a limited amount of the empirical research testing hypotheses derived from this theory. From the options below, what is a common way that terror management theory researchers operationalize mortality salience? And is this a measured or manipulated variable? Question 3 options: a) Two open-ended questions that ask participants to think and write about their own death; this is a manipulated variable. b) Two explicit-self report items where participants indicate the extent to which the idea of death causes them anxiety (participants response on a scale from 1 to 10, with 10 indicating extreme anxiety); this is a measured variable. c) Two open-ended questions that ask participants to think and write about their own death; it is a measured variable. d) Two explicit-self report items that ask participants to indicate the amount of time in a given day they think about their own mortality (participants indicate their responses on a 1 to 10 scale, with 10 indicating very frequently); this is a measured variable. e) Two open-ended questions that ask participants to think about write about experiencing uncertainty; it is a manipulated variable.