Assume John and Mary are a married couple. John is a member of a group insurance plan (through his employer) that provides group dental coverage with a$ 100 deductible and an 80% co-insurance factor. Mary is a member of an association group dental plan that has a $50 deductible and a 100% co-insurance factor. Mary's plan also provides spousal coverage. The couple's first dental claim for the year is a $250 X-ray and cleaning bill for John.

Explain how John's claim is treated under the coordination of benefits.