In an E-R Model, we can constrain the number of entities that participate in a relationship. This is often reffered to as Cardinality.
When many entities of an entity set may participate in a relationship, we express this by connecting the entity set with the relationship by an undecorated line.
Connect the Account entity set with the CustAcc relationship set with an undecorated line:
Click at the "Compare with Solution" button to see if your diagram is correct
Source: http://www.cs.sfu.ca/CC/354/zaiane/material/notes/Chapter2/node8.html