Correct, as the spousal beneficiary of an IRA you have two options — take the distributions over your lifetime, or withdraw all the account within 5 years. And actually, it’s not quite that simple!
Read this article about the rules for withdrawing from an inherited IRA.
A lot depends on how you treat the IRA itself, keeping it as “inherited” or rolling it into your account, and a lot of that depends on whether the decedent had already started taking RMDs!
So you need some professional help on this decision, based on your specifics. The best place to get it is from the IRA “custodial firm”. Or a Certified Financial Planner — not a “salesperson”!