Question

& Write the full from.
a PIN
b. PCO
C. STD
d. ISD​

Answer 1

Answer:

ISD (International Subscriber Dialling) stands for International calls

STD (Subscriber's Trunk Dialling) for Inter-state calls

PCO (Public Call Office) for local calls.

PIN Postal Index Number

Answer 2

Answer:

STD - Subscriber trunk dialling

ISD - International subscriber dialling

PCO - Public call office

PIN - Personal identification number