All of the following are correct except:
a. the highland climate, with a variety of forests, can be found in borneo.
c. new guinea is one area in the highland climate region.
b. malaysia is in the tropical climate zone and has a rainforest.
d. singapore is primarily hot and dry, which has limited its urbanization.

The correct answer is D. It is not correct that Singapore is primarily hot and dry and that it has limited its urbanization.

Explanation:

Singapore is a city-state of Southeast Asia, located on the extreme southern tip of the Malay Peninsula, 152 km north of the equator. It is spread over an archipelago made up of about 60 islands, the largest and main of which is the island of Singapore which houses the metropolis. To the north Singapore is separated from Malaysia by the Strait of Johor, to the south it is separated from the Indonesian Riau Islands by the Strait of Singapore.  

The city-state is the world's fourth largest financial center and is one of the main cosmopolitan cities on the globe, with an important role in international trade and finance. Its port is among the top five in terms of activity and traffic worldwide.

Singapore is a country with a long history of immigration. It has a varied population and the over 5 million inhabitants are mainly composed of Chinese, Malaysians, Indians and other descendants of Asians and Europeans.  

Singapore is the second most densely populated country in the world after the Principality of Monaco and in 2009 it reached the highest concentration of millionaires in relation to the population, ahead of Hong Kong, Switzerland, Qatar and Kuwait.