DSL (Digital Subscriber Line) is the best solution when telephone lines are available in a remote area but other network infrastructures, like cable or fiber, are limited. DSL uses existing telephone lines to provide internet access and is often a cost-effective solution in areas with limited connectivity options.
A . Cable requires coaxial infrastructure, which may not be available.
B . Fiber optic provides high-speed connectivity but requires specialized infrastructure.
C . Wireless network may be an option, but DSL is a better fit given the availability of telephone lines.
Reference:
CompTIA Network+ Certification Exam Guide
Official CompTIA A+ Certification Study Materials