In the Romer Model, the Production Function $Y _ { t } = A _ { t } L _ { y t }$

In the Romer model, the production function $Y _ { t } = A _ { t } L _ { y t }$ , where A_t is knowledge and L_yt is the amount of labor in the output sector:

A) exhibits constant returns to labor and increasing returns to labor and knowledge
B) exhibits constant returns to labor and increasing returns to knowledge
C) exhibits increasing returns to labor and constant returns to labor and knowledge
D) exhibits decreasing returns to labor and constant returns to labor and knowledge
E) exhibits increasing returns to labor and increasing returns to labor and knowledge