Explanation:

- S has scores higher than Q but lower than U.

- P scores more than S, but less than R and U.

- T scores higher than R.

- The third lowest score is 56.

- R scores 12 more than P.

- U is below 69 in scores.

- Q + R equals 111.

- P + T equals 137.

Let's determine scores step-by-step:

- Rank (from low to high): Q, S, P, R, T; highest rank is less than 69 (U).

- Since R scores 12 more than P, and they rank below U, P = R - 12.

- Q + R = 111 gives the value for Q once R is identified.

- P + T = 137 gives the value for T.

- Since P ranks before R, P is the third lowest at 56 (or its a critical value to use).

- Using the equations, check: Q + T = 121.

Hence, option 3, 121, is the correct answer.