A manufacturing firm is seeking to enhance its plant floor operations with a network system capable of managing large$-$scale, real$-$time processes. The firm emphasizes the need for this network to be securely isolated to prevent unauthorized or accidental communications with external networks. Given these requirements, which type of network infrastructure will BEST fit the firm$$s operational and security needs?

A$.$Hybrid cloud infrastructure

B$.$Air$-$gapped infrastructure

C$.$SDN infrastructure

D$.$ICS$/$SCADA infrastructure