How many out of the given statement(s) is (are) correct
i) Phenyl group is known to exert negative inductive effect, but each phenyl ring in biphenyl $(C_6{H}_5-C_6{H}_5)$  is more reactive than benzene towards electrophilic substitution.
ii) 7-bromo-1, 3, 5-cycloheptatriene is ionic compound whereas 5-Bromo-1,
3-cyclopentadiene can’t ionise even in the presence of  $A{g}^{\oplus }$
 iii)  
iv)  
v)