③ That's too low.

[keannu]

Doesn't it really fit the blank? Does it only have to be positive answers? I can't understand the Korean test-maker.
1. [SUP]1)[/SUP] Which doesn't belong?
B: I got 30 on the math test.
A: ____________. I hope you do better next time.

① Cheer up.
② That's too bad.
③ That's too low.
④ That's a shame.
⑤ I'm sorry to hear that.

 

[5jj]

#3 is possible, though it's the least likely.

 

[Raymott]

1. is only appropriate if there is some indication that the person is depressed or unhappy. There's no indication of this.