Beginner's problem with making a map

Q&A
1

I couldn’t successfully run this command on my terminal " pscoast -R0/360/-70/70 -Jm1.2e-2i -Ba60f30/a30f15 -Dc -G240 -W1/0 -P > GMT_mercator.ps". All i get is this error code “$ pscoast -R0/360/-70/70 -Jm1.2e-2i -Ba60f30/a30f15
-Dc -G240 -W1/0 -P > GMT_mercator.ps
pscoast [ERROR]: Must specify at least one of -C, -G, -S, -E, -I, -N, -Q and -W
-bash: -Dc: command not found”. I need help

2

Has to be one line, not spit over two. That is why it tries to run "-Dc … as a separate command which is of course not found.
If you are a beginner, why are you using GMT classic mode? Lots easier with modern mode.