To reload an SSL certificate, the appropriate service that typically handles SSL certificates needs to be restarted. In this case, 'httpd' is the correct choice because it refers to the Apache HTTP Server, which is commonly used to manage SSL certificates and would need to be restarted to apply the new certificate. Other services like 'tomcat' and 'docker' are less likely to be directly responsible for handling SSL certificates in the context of an App Host, and 'ecs-ec-ingress' does not specifically refer to a common service related to SSL certificate management.