Which audio settings should I choose when encoding from a Premiere Pro sequence

I am encoding a Premiere Pro sequence in Media Encoder - both are the latest versions. The video is for broadcast TV which is asking for H.264. I'm using Match Source - Adaptive High bitrate. 

The spec sheet from the TV station also asks for uncompressed audio, 48kHz. Uncompressed doesn't seem to be a choice. Audio format settings are AAC and MPEG. Which one should I choose? 

If the answer is MPEG, which setting: MPEG, Layer 1 or MPEG-1, Layer 2?  I see that within MPEG the bitrate goes to 448 kbps, whereas in AAC it only goes to 320 kbps. Should I go with 448? There are many more audio settings choices within MPEG as well, which I'm unsure about. 

I'm not seeing any answers within Adobe or the internet at large. 

Thanks.