option is D
Lines can have one of three cap styles: Butt, Round and Projecting Cap.
Depending on which Cap setting you choose, you get three noticeably different capped lines. Here are the options:
Butt Cap: Chops off the stroke at the ends.
Round Cap: Extends the stroke past the ends (or around the dash location) with semicircular ends. (The radius of each semicircle equals half the stroke weight.)
Projecting Cap: Extends the stroke past the ends (or around the dash location) with squared ends. (The amount of each extension equals half the stroke weight.)
Unless otherwise specified, HTML5 Canvas lines are defaulted with the butt cap style.