Answer:
a) commitment.
Explanation:
This shows that Brenda and Jonathan's relationship has a high level of commitment. In Robert J. Sternberg's triangular theory of love, commitment is the decision to stay in the relationship to achieve common goals and to remain in the relationship even when facing problems. As Brenda and Jonathan have a long-term commitment Jonathan's commitment to caring for Brenda is shown by his retaring to take care of her.