patients has a family history of Marfan's syndrome has recently been diagnosed with the condition.. Echocardiography

One of your patients who has a family history of Marfan's syndrome has recently been diagnosed with the condition. What is the most important investigation to monitor their condition?
A.A Urea and electrolytes
B.A Echocardiography***
C.A Spirometry
D.A Electrocardiogram
E.A DEXA scan.