c
\(\begin{array}{l}
Clearly\,the\,time\,taken\,by\,the\,particle\\
to\,reach\,the\,highest\,{\rm{ point}}\,is\,given\,by\\
V = u - gt\\
or,\,t = \frac{{u - v}}{g} = \frac{{19.6 - 0}}{{9.8}}\\
or,\,t = 2\,s.\\
Therefore,\,the\,particle\,will\,reach\,at\,the\\
starting\,{\rm{point}}\,{\rm{itself}}\,{\rm{after}}\,{\rm{4}}\,s.
\end{array}\)