To reduce current defects per million a statistically significant amount, which of the following recommendations would you most likely recommend? $($Assume that you seek Cpk $>1\mathrm{.}33$ or a process mean for shelf life to be at least $4*$ inherent standard deviation greater than the LSL$.)$ Note: While multiple solutions may be found to optimize the process, please select among the following options. $($Optional: To verify your answer, subset data within your recommend ranges for the X variables and assess the process capability relative to their desired goal.$)$

a$.$ Recommend a seal strength $>7$ with packing temp $<15$

b$.$ Recommend a seal strength $>5,$ the other variables do not matter and may be kept within their current range of settings $($i$.$e$.,$ same as found in the data set$).$

c$.$ Recommend a seal strength $>4$ and container size $=32$

d$.$ Recommend a container size $=32$ with packing temp $<10$