How much Boric Acid is required to render 25 mL of the following eye drops isotonic?

		SCE
Streptomycin Sulphate	6.25%	0.06 g
Boric Acid	qs	0.5 g
Chlorbutol	0.5%	0.24 g
Water for Injection to 25 mL

Select one:

a.

990.3 mg

b.

495.8 mg

c.

202.5 mg

d.

405.0 mg

e.

810.1 mg