Question: What is the basis for the 3GPP circuit-switched multimedia call, and what ITU-T Recommendation does it variant from?
Option 1: The 3GPP circuit-switched multimedia call is based on H.323, which is a variant of the ITU-T Recommendation H.320.
Option 2: The 3GPP circuit-switched multimedia call is based on 3G-324M, which is a 3GPP-variant of the ITU-T Recommendation H.324.
Option 3: The 3GPP circuit-switched multimedia call is based on SIP, which is a variant of the ITU-T Recommendation H.225.
Option 4: The 3GPP circuit-switched multimedia call is based on SDP, which is a variant of the ITU-T Recommendation H.245.
Explanation: The correct answer is Option 2 because the 3GPP circuit-switched multimedia call is indeed based on 3G-324M, which is a 3GPP-variant of the ITU-T Recommendation H.324, as stated in the provided text.