Concept:Diminishing returns occurs when adding more variable inputs to fixed factors leads to smaller increases in output.
Explanation:The law of diminishing returns applies in the short run, where at least one factor is fixed.
Output rises initially, then slows down because each extra unit of a variable input gets less and less help from the fixed factor.
Common causes include constant technology and limited or fragmented land, both of which restrict further production gains.
An increase in variable inputs is the direct situation that causes diminishing returns, not a separate cause.
Technological innovations improve productivity and shift the production function upward, so they actually prevent or delay diminishing returns.
Thus, technological innovation is not a cause of diminishing returns.
Answer:D. Technological innovations