A compressor takes five minutes to build from 50 to 90 psi at about 1200 rpm. What does this indicate in Alberta's trip air brake inspection context?

1. It fails the listed build-up performance of 50 to 90 psi within three minutes
2. It exceeds the requirement because slower build-up is safer
3. It is acceptable only if the load is light
4. It proves the trailer supply valve is working