The Change from Religious to Lay Teachers at Roman Catholic

Multiple Choice

The change from religious to lay teachers at Roman Catholic schools has been partly attributed to the decline in the number of women and men entering religious orders. The percent of teachers who are lay teachers is given by where t is measured in decades, with corresponding to the beginning of 1960. ​
Find the year when the percent of lay teachers was increasing most rapidly.
​

A) 1985
B) 1962
C) 1976
D) 1986
E) 1989