Which of the following is the important mobile and telephone services providing company of Jammu and Kashmir?

The correct answer is D. All of these.

BSNL, Airtel, and Aircel are all major mobile and telephone service providers in Jammu and Kashmir. BSNL is a state-owned telecom company that offers a wide range of services, including voice, data, and internet. Airtel is a private telecom company that is one of the largest in India. Aircel is another private telecom company that offers a variety of services, including voice, data, and internet.

All three companies have a strong presence in Jammu and Kashmir and offer a variety of services to customers. They are all reliable and offer good customer service.