Task: Question Answering
Input (English): Problem: the bases of a hemisphere and a cone are equal. if their heights are also equal then ratio between their curved surface area is —
Options: ['a. 1: √ 2', 'b. √ 2 ∶ 1', 'c. 1: 2', 'd. 2: 1', 'e. none of these']
Output (English): b