Your question is incomplete because you have not provided the answer options, which are the following:
A. Change "Abashed" to "Abashing"
B. Change "mortifying" to "mortified"
C. Change "to rewrite" to "rewriting"
D. Change "beginning" to "began"
Answer:
B. Change "mortifying" to "mortified"
Step-by-step explanation:
Adjectives ending in -ing describe a quality or the effect that something can have on someone. On the other hand, adjectives ending in -ed describe how someone feels. Thus, the writer feels ashamed, embarrased or humiliated as a result of the harsh criticism.
The rest of the options are grammatically correct, since "Abashed" is the beginning of a participle clause, "to rewrite" is a full infinitive after the verb decided, and "beginning" is a noun.