Q: Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.
Problem: the weight of every type a widget is the same, the weight of every type b widget is the same, and the weight of every type c widget is the same. if the weight of 7 type a widgets is equal to the weight of 4 type b widgets, and the weight of 3 type b widgets is equal to the weight of 7 type c widgets. what is the ratio of the total weight of 1 type a widget and 1 type b widget, to the total weight of 1 type b widget and 1 type c widget ?
Options: a. 5: 4, b. 7: 6, c. 9: 8, d. 11: 10, e. 13: 12
A:
d