c
Net force on particle must be zero i.e. \(\mathrm{q} \overrightarrow{\mathrm{E}}+\mathrm{q} \overrightarrow{\mathrm{V}} \times \overrightarrow{\mathrm{B}}=0\)

Possible cases are

\((i)\) \(\overrightarrow{\mathrm{E}} \& \overrightarrow{\mathrm{B}}=0\)

\((ii)\) \(\overrightarrow{\mathrm{V}} \times \overrightarrow{\mathrm{B}}=0, \overrightarrow{\mathrm{E}}=0\)

\((iii)\) \(\mathrm{q} \overrightarrow{\mathrm{E}}=-\mathrm{q} \overrightarrow{\mathrm{V}} \times \overrightarrow{\mathrm{B}}\)

\(\overrightarrow{\mathrm{E}} \neq 0 \& \overrightarrow{\mathrm{B}} \neq 0\)