Use the Statement Below to Answer the Question(s) That Follow

Use the statement below to answer the question(s) that follow.
Uranium ²³⁸U decays to lead ²⁰⁶Pb with a half life of 4.5 billion years.
-Which isotope is the parent?

A) ²⁰⁶Pb
B) ²³⁸U
C) 4.5 billion
D) both ²³⁸U and ²⁰⁶Pb are parents
E) both ²³⁸U and 4.5 billion years are termed "parents"