“a large quantity of lacing is a disadvantage. when soaked with water [samurai armor] becomes very heavy and cannot be quickly dried; so that in summer it is oppressive and in winter liable to freeze. moreover, no amount of washing will completely free the lacing from any mud which may have penetrated it, and on long and distant campaigns it becomes evil smelling and overrun by ants and lice, with the consequent ill-effects on the health of the wearer. it is also easily damaged because it will retain a spear instead of letting it glide off harmlessly.”
—sakakibara kozan,
chukokatchu seisakuben

which sentence states the main idea of this paragraph?
a.
no amount of washing will completely free the lacing from mud.
b.
it will retain a spear instead of letting it glide off harmlessly.
c.
when soaked with water it becomes heavy and cannot be quickly dried.
d.
a large quantity of lacing is a disadvantage.