Greg leases an apartment from Sally for one year. The lease requires Sally's consent for all obligations under the lease. After three months into the lease, Greg receives an internship for six months in another state. Greg sublets the apartment for the next six months to John without telling Sally. John pays the rent for only four months.For the last two months of the six-month term, Greg is:
a. liable for the rent because John defaulted on the sublease
b. liable for the rent because his assignment lacked Sally's consent
c. not liable for the rent because Sally accepted rent from the assignee
d. not liable for the rent because the original lease terminated when the apartment was subleased.