Thank u herman and christopher for correcting my mistakes,

Actually, why I switched to minor & major is, I thought when changing from B to key F

Major chords are the i iv v F B C respectively

Minor chords are the ii iii vi G A D respectively, so I thought when transposing B all minor and major should accompany with the key of F.

Accordingly, in the key of F the note A is 3rd minor, then how it is possible to shift to major note. I don't understand it?