Explanation:

- Observe the pattern in the given codes:

- For 'POTATO':

- P(16) + 16 = 32, O(15) + 15 = 30, T(20) + 20 = 40, and so on.

- For 'TURNIP':

- T(20) + 20 = 40, U(21) + 21 = 42, R(18) + 18 = 36, and so on.

- The pattern involves taking the position of the letter in the alphabet and adding it to the position.

- Apply the same logic to 'RADISH':

- R(18) + 18 = 36

- A(1) + 1 = 2

- D(4) + 4 = 8

- I(9) + 9 = 18

- S(19) + 19 = 38

- H(8) + 8 = 16

- Option 4 matches this pattern: 36-2-8-18-38-16