For those who still think that "an uniform" should be accepted .... say these phrases out loud:
[consonant 'u' sound]
a unique experience
[vowel 'u' sound]
an undergraduate, an underground, an unpleasant experience.
[consonant 'h' sound]
[vowel 'h' sound]
If you are still confused, look up Youtube clips.
The capital 'I' and the lower case 'L' = 'l' look the same with this font. My correct answer was marked wrong. I also have problems with Io (I), and lo 'Lo' lower case. The font should be changed so that the two letters actually look different. Strictly speaking, the 'I' looks thicker in the answers, but not in texts generally.