En el mercado central, hay una tienda que (vender) recuerdos (souvenirs).
a. vendec. vendesb. vendend. vendo

If you're talking about you it would be vendes
if your talkig about he she or you formal it would be vende
if your talking about yourself it you be vendo
if your talking about them it would be venden

B. Venden It is venden because recuerdos is plural. Venden recuerdos is correct . I'm terrible at explaining

The correct answer is d

Ithink its b) built underground reservoirs