What is the primary challenge associated with bottleneck items in a sourcing strategy?

What is the primary challenge associated with bottleneck items in a sourcing strategy?

These items are associated with a high number of alternative suppliers, leading to frequent quality issues.

They involve low supply risk but require large expenditures, making them difficult to manage.

They demand disproportionate effort relative to their spend and are typically high supply risk with limited alternatives.

These items offer significant cost$-$saving potential but require complex logistics and multiple sourcing strategies.