Hello Arpita,  

The option (2) A and C only :is correct as because; 

(A)  This option says; The reaction between NaOH and 1 - chloropentane predominantly follows an SN2 reaction which absolutely correct as the stability degree of SN2 reaction is  - 1°> 2° >3° . And here the carbon is 1° so it is highly stable. 

(B)  Here the carbon is 3° , it is very less stable. So, SN2 is not favorable in this condition. 

(C) The reaction of 1 - chloropentane occurs at slower rate than 1 - bromopentane;  the leaving ability of Bromine is greater than chlorine.

Hope it helps. 

Thank you.