Identify the sentence below that correctly creates parallelism with correlative conjunctions.
a. When Bethany's graduation day came, she was both sad to leave high school and it was exciting to begin college.
b. When Bethany's graduation day came, she was both sad to leave high school and in addition she was excited to begin college.
c. When Bethany's graduation day came, she was both sad to leave high school and would be excited to begin college.
d. When Bethany's graduation day approached, she was both sad to leave high school and excited to begin college.