Two machines, M$1$ and M$2,$ are making pins which must have a diameter of $8cm+-\mathrm{.}01cm$ or they are rejected. Dotplots of $50$ pins from each machine are displayed below. Each dot represents one diameter. They are both on the same scale as given below.M$1$

By simply looking at the dotplots, i$.$e$.$ without doing any calculations or counting, compare M$1$ and M$2$ in light of:

a$.$ Which process is best as is$?$ M$1$ M$2$

b$.$ Which is most off center? M$1$ M$2$

Circle one of the above choices

Circle one of the above choices

c$.$ And which is the most stable?

M$1$ M$2$

Circle one of the above choices