Final answer:
The correct statement to add the string "Wendy" to the list at index[0] is a) names[0] = 'Wendy'.
Step-by-step explanation:
The correct statement to add the string "Wendy" to the list at index[0] is a) names[0] = 'Wendy'. This statement assigns the value 'Wendy' to the element at index 0 in the list 'names'. The other option, b) ('Wendy'), is not a valid statement to add an element to a list.