Explanation:

- Start from Tree M, which is 3 km west of N.

- P is situated 2 km north of M.

- O is 3 km east of P.

- Q is directly south of O, at a distance of 6 km.

- N is located between O and Q making it 3 km south of O.

- S is positioned halfway between M and R, with a distance of 1 km from M.

- T is 3 km west of S.

- U is north of T, with the same distance from T as S is from P.

- Calculation: Since S is 1 km from M and P is 2 km north of M, the distance between S and P is 2 km.

- Therefore, the distance between T and U is also 2 km.

- Correct Answer: Option:3, 2 km