It looks like both apply. Cancellation due to inactivity (the second part of section 4a) means your points will be forfeited if there's no activity on your account in 12 months (also known as "soft expiration"). Expiration (first part of 4a) means the points are forfeited 60 months from the date they're earned of not used, regardless of whether or not there's other activity on the account (also known as "hard expiration").