Nondeliverable Forward Exchange Markets in Centers Such as Hong Kong

Nondeliverable forward exchange markets in centers such as Hong Kong and Singapore help to circumvent which problem?

A) loss of goods shipped from Hong Kong and Singapore
B) inconvertible currencies cannot be traded in foreign markets
C) lag between the spot exchange date and the value date
D) high travel costs from Asia to "traditional" foreign exchange markets
E) unstable currencies that hold no purchasing power