किसी जनसंख्या का निर्भरता अनुपात (Dependency ratio) मुख्य रूप से निम्नलिखित में से किससे प्रभावित होता है?

A large portion of the non-ecumene region of the Earth has remained sparsely populated primarily because of:

A significantly low sex ratio (fewer females per male) is most typically associated with which type of urban centers due to male-selective migration?