a) browsing offline
b) reduction of server load
c) speed
d) asynchronous

Answer: d
Explanation: Application cache can be helpful in so many ways like we can browse offline, as the cached resources are at local level hence they load at faster speed, it also reduces the load of the server. Asynchronous is one of the problems with the use of application cache due to this the resources which are not required like JavaScript or images will also be downloaded.