In this question, we are given two lists: List I and List II. We need to match the elements in List I with their corresponding uses in List II.

List I contains the elements Li, Na, K, and Cs. List II contains the uses of the elements, which are as follows:

1. Li (Lithium) is a time keeper in atomic clocks.

2. Na (Sodium) is used in batteries.

3. K (Potassium) is involved in the transfer of nerve impulses.

4. Cs (Cesium) is responsible for controlling the water content in the blood.

We need to match the elements in List I to their corresponding uses in List II. Looking at the options, we find that option 1 matches the elements and their uses correctly. Therefore, the correct answer is option 1.

The correct matching for List I and List II is as follows:

A - 1, B - 2, C - 3, D - 4

Hence, the correct answer is option 1.