Consider the following statements with respect to Discrete Fourier Transform (DFT) : 1. It is obtained by performing a sampling operation in the time domain. 2. It transforms a finite duration sequence into a discrete frequency spectrum. 3. It is obtained by performing a sampling operation in both time and frequency domains. Which of the above statements is/are correct ? (a) 1 and 2 only (b) 2 and 3 only (c) 1 only (d) 3 only