Question

select the test - tube holder.

Explanation:

A test - tube holder is a tool used to hold test - tubes safely, especially when heating them. The third image shows a typical test - tube holder with two prongs to grip the test - tube. The first image is an unknown object, and the second is a stand which is not a test - tube holder.

Answer:

The third image (the one that looks like a pair of tongs with a curved shape for holding a test - tube).