BOTH INTERNATIONAL and INLAND

Which statement is TRUE of a 30-meter sailing
vessel underway?

A. She must show sidelights and a sternlight in
restricted visibility.
B. She may show an all-round white light at the
top of the mast.
C. She need not show a sternlight if she is showing
all-round lights at the mast.
D. If she is using propelling machinery, she shall
show forward a shape consisting of two cones
apexes together.