In March $2000,$ lightning hit a power line in Albuquerque, New Mexico. The strike caused a massive surge in the surrounding electrical grid, which in turn started a fire at a local plant owned by Philips Electronics and damaged millions of microchips. As a result, the mobile phone company Ericsson, which purchased the microchips from Philips and had no alternative source, encountered production problems that lasted for months and caused a loss of $$400$ million in sales. If Ericsson had been using in$-$house manufacturing, which advantage would have helped them in this scenario?

a$.$ Making components and raw materials in$-$house allows the company more control over deliveries.

b$.$ When components and raw materials involve intellectual property, making affords complete protection of the intellectual property.

c$.$ In$-$house production is advantageous because it secures the supply source.

d$.$ In$-$house sourcing is sometimes the only option for components and raw materials that are scarce, highly specialized, or particularly of national security concern.