How is the graph of the parent function y=x² transformed to produce the graph of y=3(x+1)²?

a) It is translated 1 unit right and compressed vertically by a factor of 3.

b) It is translated 1 unit left and compressed vertically by a factor of 3.

c) It is translated 1 unit right and stretched vertically by a factor of 3.

d) It is translated 1 unit left and stretched vertically by a factor of 3.