Concept:
Core input industries are the basic industries that supply essential raw materials and intermediate goods required by several other sectors of the economy. These industries form the backbone of industrial development by providing key inputs for infrastructure, manufacturing, construction, and capital goods.
Examples of core input industries include:
• Steel
• Cement
• Coal
• Electricity
• Crude Oil
• Natural Gas
• Fertilizers
• Refinery Products
Step 1: Examine each of the given industries.
\[
\begin{aligned}
\text{Cement} &\rightarrow \text{Core input industry},
\text{Automobiles} &\rightarrow \text{Consumer/Manufacturing industry},
\text{Textiles} &\rightarrow \text{Consumer industry},
\text{Steel} &\rightarrow \text{Core input industry}.
\end{aligned}
\]
Step 2: Identify the industries that are classified as core input industries.
Only Cement and Steel are core industries supplying essential inputs to other sectors.
Hence,
\[
\boxed{
\text{A and D only}
}
\]
This corresponds to
\[
\boxed{\text{(C) A and D only}}
\]