Correct Answer:
Option B - Substitute that its by that it's. Here it's gives sense of (it is), not possessive adjective (its).
Correct Sentence-
In fact, climbing fern is spreading so rapidly that it's now the state's worst invasive weed.
B. Substitute that its by that it's. Here it's gives sense of (it is), not possessive adjective (its).
Correct Sentence-
In fact, climbing fern is spreading so rapidly that it's now the state's worst invasive weed.