The elements commonly used for making transistors are :

Options

A. C and Si
B. Ga and In
C. P and As
D. Si and Ge

Explanation

To determine the elements commonly used for making transistors, we need to identify which of the given options are semiconductors. Here’s a step-by-step solution:

### Step 1: Identify the Elements in the Options
The options provided are:
1. Carbon-Silicon
2. Gallium-Indium
3. Phosphorus-Arsenic
4. Silicon-Germanium
...