Assume That a Country's Production Function Changes From $Y = 2 \sqrt { K }$

Multiple Choice

Assume that a country's production function changes from $Y = 2 \sqrt { K }$ to $Y = 3 \sqrt { K }$
. Which of the following events could explain the change in this production function?

A) the disappearance of diminishing returns from the production function
B) the development of new technology in production
C) greater capital accumulation
D) less depreciation due to better capital stock maintenance.