With a huge market share and high growth potential, the first Apple iPod was a promising product. Over the years, the device eventually stopped creating a significant impact and customer demand decreased. Thus, the iPod became a $\_\_\_\_.$

With a huge market share and high growth potential, the first Apple iPod was a promising product. Over the years, the device eventually stopped creating a significant impact and customer demand decreased. Thus, the iPod became a $\_\_\_\_.$

cat

dog

star

cash cow

problem child