In its 10-K for fiscal year 2018, Tesla, Inc. disclosed the following information about its warranties:

"We provide a manufacturers warranty on all new and used vehicles, production powertrain components and systems and energy storage products we sell We accrue a warranty reserve for the products sold by us, which includes our best estimate of the projected costs to repair or replace items under warranties and recalls when identified. These estimates are based on actual claims incurred to date and an estimate of the nature, frequency and costs of future claims"

What type of warranties are described here?

a) Agreement-type (also called indenture warranties)

b) Amortizing-type (also called impairment warranties)

c) Assurance-type (also called base warranties)

d) Service-type (also called extended warranties)