Which of the following is considered a limitation of RIP v1?

RIP v1 does not send subnet mask information in its updates.
RIP v1 is not widely supported by networking hardware vendors.
RIP v1 consumes excessive bandwidth by multicasting routing updates using a Class D address.
RIP v1 requires enhanced router processors and extra RAM to function effectively.
RIP v1 does not support load balancing across equal-cost paths.
RIP v1 authentication is complicated and time-consuming to configure.

ccna exploration 2 chapter 5 Exam Question And Answers 

Which of the following is considered a limitation of RIP v1?