GATE Electronics and Communications (EC) 2015 Shift 2 Solved Paper

Consider a binary, digital communication system which used pulses $\mathit{g}\left(\mathit{t}\right)$ and $-\mathit{g}\left(\mathit{t}\right)$ for transmitting bits over an AWGN channel. If the receiver uses a matched filter, which one of the following pulses will give the minimum probability of bit error?