When two tuning forks (fork 1 and fork 2 ) are sounded simultaneously, 4 beats per second are heard. Now, some tape is attached on the prong of the fork 2 . When the tuning forks are sounded again, 6 beats per second are heard. If the frequency of fork 1 is $200 \mathrm{~Hz}$, then what was the original frequency of fork $2 ?
(A) $202 \mathrm{~Hz}$
(B) $200 \mathrm{~Hz}$
(C) $204 \mathrm{~Hz}$
(D) $196 \mathrm{~Hz}$