Explanation:

- To find the average of the first 43 natural numbers, use the formula for the average of the first n natural numbers: (n+1)/2.

- So for n=43, the average is (43+1)/2 = 44/2 = 22.

- Option 1 (33): Incorrect, this doesn’t fit the formula for n=43.

- Option 2 (44): Incorrect, this is the sum divided by 1, not the average.

- Option 3 (43): Incorrect, same as above.

- Option 4 (22): Correct. This matches the formula and calculation.