because of vs due

[clock60]

The number of acres destroyed by wildfires, which have become an ongoing threat due to drought and booming population density, have increased dramatically over the past several years, prompting major concern among local politicians.

D) have become an ongoing threat due to drought and booming population density, has increased
E) have become an ongoing threat because of drought and booming population density, has increased

when to use due to and when to use because of

[GoISB]

IMO E
"Because of" usage is correct. Due to usage is incorrect.

[3Gs]

"due to" is not a correct idiom .....GMAT verbal review example 98

[clock60]

thank you guys for showing right path