Correct Answer: (a) increasing
Solution:The Cobb - Douglas production function, named after Paul H. Douglas and C.W. Cobb, is a famous statistical production function. It is derived to study the whole of American manufacturing industries.
In the Cobb - Douglas production function, Q = AKᵃ Lᵇ, where ‘a’ and ‘b’ are output elasticity of capital and labour, respectively. If a + b > 1, the underlying return to scale will be increasing.