The correct answer is C. Self-conscious with a spikey haircut, the student looked at the floor while her teacher talked.
Step-by-step explanation:
Words such as "self-conscious" or " with a spikey haircut" are modifiers because they describe a noun, in this case, the student. Moreover, these modifiers should be placed right before the noun describe to make clear which is the person or object described. Otherwise, the meaning would be unclear and even confusing. For example, in "looked at the floor with a spikey haircut" it is suggested the one with the haircut is the floor, which is illogical. In this context, the best option is C because in this, the modifiers are placed right before the word "student" and this clarifies the one that is self-conscious and has a spikey haircut is the student.