Suppose you break your promise to visit your dying grandmother on the grounds that you can create more happiness by partying with your friends. this utilitarian view of the situation seems to conflict with:

 View of common sense of ones obligations/duty towards other people.

Explanation:

According to the theory of utilitarians, increasing the happiness and right actions should be done for the affected or suffering person. As a duty of a person towards their close ones, he/she should create the atmosphere of well being by acknowledging the interest of other people.

According to the situation mentioned in question, an individual doing party on the basis of obligation to create happiness for his/her grandmother instead of meeting her at her dying stage indicates view of common sense of performing duty for suffering people in terms of utilitarians.

answer; i do believe its (b) 12.5 years of age;