please provide answer to the questions

The engineering company needs to assure a sufficient durability of the component, in case they switch from their old supplier to a new one. In order to meet strict maintenance requirements, the optimal life cycle of the components is 1.5 years +/- 0.75 years. D now represents the expected life cycle of the components offered by the new supplier and D is normally distributed with a mean of 2 years and a variance of 0.5^2 (standard deviation=0.5 years): D ~ N(2; 0.52). How many pieces don't comply with the life cycle specification? 15% 31% 45% 49%