Final answer:
Gregor's parents and the clerk are likely to exhibit shock, fear, and bewilderment upon seeing him, aligning with dramatic and troubled emotional responses similar to those expressed in the provided text excerpts.
Step-by-step explanation:
The expressions on the faces of Gregor's parents and the clerk in the last panel can best be described as a mix of shock, fear, and bewilderment. These descriptions capture a moment of intense emotional reaction, likely characterized by wide eyes, open mouths, and possibly recoiling movements.
The text fragments provided don't directly reference Gregor's scenario, but they exemplify various expressions of surprise, fear, and confusion that would fit the characters' reaction upon seeing Gregor in his transformed state.
While none of the exact phrases presented in the question's options are used in the text excerpts given as reference, the general theme of a dramatic and troubled emotional response is evident and aligns well with the descriptions of fearful and horrified expressions.