Dependent / Related Options
Module is designed to set related-to-option values for goods (eg. colour and size). Thus it gives a way to account goods on stock depending on option combinations. Option combinations also can have different prices.
Fields "Parent option" and "Parent option value" by a certain product at the admin panel (tab "Options") are used to create related options.
By a store front the related option is shown only after choosing some parent option value. After that related-to-option values are available according to a chosen parent option value. For example, related-to-colour size.