Which operator concatenates two strings?

A company used a partner company to develop critical components of an application. Several employees of the partner company have been arrested for cybercrime activities. Which of the following should be done to protect the interest of the company?

A. Perform a penetration test against the application B. Conduct a source code review of the application C. Perform a baseline review of the application D. Scan the application with antivirus and anti-spyware products.

Explain entity-relationship (ER) diagrams.

What will be an ideal response?