When Building Medical Words,what Should You Do When Adding Two

Multiple Choice

When building medical words,what should you do when adding two combining forms to a suffix that begins with a consonant?

A) Keep the vowel in the first combining form and drop it in the second.
B) Drop the vowel in the first combining form and keep it in the second.
C) Keep the vowels in both combining forms.
D) Drop the vowels from both combining forms.