Shirabe
Noun
English jmdict
1
noun (common) (futsuumeishi) arc
We can eliminate C and D since they are irrelevant to the generation of the arcs.
Expression Godan
English jmdict
1
expressions (phrasesGodan verb with 'ku' ending to draw an arc (e.g. with a compass);to describe an arc (e.g. through the air);to form an arc