When Is the Tax Incidence the Same as Who Ultimately

When is the tax incidence the same as who ultimately bears the tax

A) When the tax is levied on the buyer and the demand is perfectly elastic.
B) When the tax is levied on the buyer and the supply is perfectly elastic.
C) When the tax is levied on the seller and the demand is perfectly inelastic.
D) When the tax is levied on the seller and the supply is perfectly elastic.