United Launch Alliance launched Atlas V Rocket

Current Context: The United Launch Alliance launched the Atlas V rocket from Cape Canaveral Space Force Station of Florida.

• The rocket carried SBRIS (Space-Based Infrared System) Geo-5 Missile Warning Satellite.
• Its purpose is to provide missile warning, missile battlespace and defence characterization. Its weight is 4850kilograms.
• The SBRIS is a Space Tracking and Surveillance System which meets Infrared Space Surveillance of the United States Space Force System.
• The Atlas is a two-stage rocket that is fueled with rocket grade kerosene and liquid oxygen in its first stage and hydrogen and liquid oxygen in the second stage.
• Static Part: 
• HQ of United Launch Alliance: Centennial, Colorado, United States

Question: 

Q.1 Which of the following rocket manufacturer launched the Atlas V rocket which carried the SBRIS (Space-Based Infrared System) Geo-5 Missile Warning Satellite?
a. Blue Origin
b. Space X
c. Astra Space
d. United Launch Alliance