The correct answer is (A) 1. The blockage of a blood vessel; an obstruction in a blood vessel. 2. An inserting in a calendar of an additional day or other period as an adjustment for accuracy. 3. The period inserted. 4. The prayer that follows the final petitions of the Lord's Prayer in a Eucharistic service.

Examples of use:

• An embolism was the cause of his stroke..
  
  
• An embolism differs from a thrombosis, which is the formation of a blood clot within a blood vessel.