A long string is constructed by joining the ends of $2$ shorter strings. The tension in thestrings is the same but string I has $4$ times the linear mass density of string II$.$ When asinusoidal wave passes from string I to string II:A$)$ the frequency decreases by a factor of $4$B$)$ the frequency decreases by a factor of $2$C$)$ the wave speed decreases by a factor of $4$D$)$ the wave speed decreases by a factor of $2$E$)$ the wave speed increases by a factor of $2$