During COVID$-19,$ the closing of international borders led to stock$-$outs of supplies for import assemblers. As a result, the import assemblers could not see their products even when the domestic economy started reopening. Such firms risked their survival mainly because of what reasons?

a$.$ loss of revenue abroad due to failure of inbound supplies

b$.$ omnichannels

c$.$ loss of revenues due to failure of inbound supplies

d$.$ increase of market share at home to firms that are able to continue to meet domestic demand during the pandemic