Answer:
economical reasons
Explanation:
A metropolitan area network (MAN) is formed by an aggregation of multiple local area network (LAN) that are interconnected using backbone provided by an internet service provider (ISP). A metropolitan area network (MAN) spans for about 5 kilometers to 50 kilometers in size.
Basically, a metropolitan area network (MAN) spans across a geographic area such as a city and it's larger than a local area network (LAN) but significantly smaller than a wide area network (WAN).
Hence, a wide area network (WAN) is designed to span over a very large geographical area and as such would cost more in implementing than a metropolitan area network (MAN) would cost.
This ultimately implies that, metropolitan area network (MAN) speeds are faster than WAN speeds because of economical reasons.