Connectivity to other systems should be established correctly before testing the new application. If interfaces, data flows, network connections, and system dependencies are not ready before testing, the test results may be incomplete or misleading. Testing should evaluate the application in an environment that reflects required integration points. Waiting until implementation is too late because connectivity failures could disrupt production. Waiting until maintenance would mean the issue was not controlled during development. Internal audit should review whether system interfaces were identified, documented, configured, secured, and included in test planning. Correct connectivity before testing supports valid integration testing and reduces implementation risk. Therefore, Option A is correct.