The products formed when sodium reacts with cold water are:

The correct options are
B sodium hydroxide
C hydrogen gas
Alkali metals react vigorously with cold water to form respective metal hydroxides and hydrogen gas. Sodium reacts with cold water to form sodium hydroxide and hydrogen gas. The reaction involved is:

$\mathrm{Na}\left(s\right)+H_{2}O\left(l\right)\stackrel{}{\to }\mathrm{NaOH}\left(\mathrm{aq}\right)+H_2\left(g\right)$