Question:
Which position did Giovanni Antonio Grassi hold in Apr, 1840?

Context:
 Giovanni Antonio Grassi holds the position of rector from Jan, 1840 to Jan, 1842. 
 Giovanni Antonio Grassi holds the position of President of Georgetown University from Oct, 1812 to Jun, 1817. 
 Giovanni Antonio Grassi holds the position of provincial superior from May, 1831 to Jan, 1835.

Answer:
rector