A method of sexual reproduction in which two gametangia fuse to produce a zygote is known as gametangial ………...

Explanation

**Step-by-Step Solution:**

1. **Understanding Gametangia**: Begin by defining what gametangia are. Gametangia are the structures that produce gametes, which are the reproductive cells involved in sexual reproduction. They can be found in various organisms, including fungi and certain plants.

2. **Identifying the Process**: The question specifies a method of sexual reproduction involving the fusion of two gametangia. This fusion is a critical step in the formation of a zygote, which is the result of fertilization.

3. **Describing the Fusion**: When two gametangia come together, they undergo a process where they fuse to form a single structure. This process is essential for the formation of a zygote, which is the fertilized egg cell.

...