Which is one determinant of a health sources credibility

because health skills are tools and strategies and also practical skills are also something you need to learn (like tools and strategies) and put it in reality.

yes because there are aliens

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.