KNITTING -- what does "alternate" mean in this pattern instruction?

Question

Dec one st at each end of next and foll alt rows until 52 sts remain.

Answer 1

Alternate means every other row.

Answer 2

you decrease one stitch at the beginning and end of the next row and then follow ever other row until 52 stitches remain.

Answer 3

Every other row.  For example, if you were to decrease in row 33, then you would also decrease in 35, 37, 39 etc. until you had 52 stitches left on the needle.