Explanation:

The USA administration announced a new trilateral security partnership for the Indo-Pacific between Australia, the U.K. and the U.S. (AUKUS).

• The security grouping AUKUS will focus on advancing strategic interests in the Indo-Pacific region
• A central feature of the partnership would involve a trilateral 18-month effort to help Australia acquire nuclear-powered submarines which are quieter, more capable (than their conventional counterparts) and can be deployed for longer periods, needing to surface less frequently.
• The partnership would also involve a new architecture of meetings and engagements between the three countries and also cooperation across emerging technologies (applied AI, quantum technologies and undersea capabilities).
• Australia has felt increasing pressure from an assertive China, like other countries in the region, and has sought to strengthen its partnerships with India, the U.S. and the U.K., including through ‘plurilateral’ forums.
• However, as in the case of the Quad, the U.S. officials denied the partnership was a response to China.

Hence option 2nd is correct.