Mont. Code Ann. § 30-2-601
Buyer's rights on improper delivery
30-2-601 . Buyer's rights on improper delivery. Subject to the provisions of this chapter on breach in installment contracts ( 30-2-612 ) and unless otherwise agreed under the sections on contractual limitations of remedy ( 30-2-718 and 30-2-719 ), if the goods or the tender of delivery fail in any respect to conform to the contract, the buyer may:
(a) reject the whole; or
(b) accept the whole; or
(c) accept any commercial unit or units and reject the rest.