A metal dissolves in dilute HCl in the absence of air to form a pale green solution that turns yellow upon exposure to air. The metal could be :

In the absence of air, iron dissolves in diluted HCl to generate a light green solution that becomes yellow when exposed to air.

iron + hydrochloric acid →iron chloride + dihydrogen gas

$\mathrm{Fe}\left(s\right)+2\mathrm{HCl}\left(aq\right)\to {\mathrm{FeCl}}_2\left(aq\right)+{\mathrm{H}}_2\left(g\right)\uparrow$

In water,${\mathrm{FeCl}}_2\left(\mathrm{aq}\right)$  is probably the pale green  $\left[{\mathrm{FeCl}}_2\right(\left(\mathrm{OH}{)}_2{)}_4\right]$ complex. Hence, option A is correct.