Need your help O gurus!

See chart below.
vendor 1 vendor 2 vendor 3 vendor 4 Min. Cost Min. supplier
part 1 $1 $2 $4 $5 $1
part 2 $7 $10 $8 $11 $7
part 3 $15 $11 $14 $12 $11

I am struggling with a formula that will generate the name of the Min. Cost
supplier in the last column. For example, for part 1, the min. cost supplier
is vendor 1; for part 3 it is vendor 2.

What formula can I use to generate this automatically?

Thanks
Rajan