Yes, but if you have good COBOL knowledge, you find a job in nearly every mainframe related project. Every kid knows C or Java, but Mainframe knowledge, which include COBOL and REXX, is rare and needed for some decades. Beside the countless legacy applications, there are lots of new programms, interfaces, batch-jobs still written in COBOL. Many Codegenerator produce COBOL code for the mainframe and C for the PC. But, it is a terrible language.

I have programmed in more than a dozen programming languages, but I never managed to write an acceptable bit of VisualBasic. This language tends from my point of view to destroy any programming style, I hate it and still have to use it. I would avoid it for education purposes.

From your alternatives C++ gives you the chance to learn everything you need from the basics, depends on the teacher and you.

To learn OO take smalltalk, that will influence (positivly) every piece of code you write in the future. But if you get the chance try out some assembler, which will give you some understandig how the languages/computer work.

And it came to pass that in time the Great God Om spake unto Brutha, the Chosen One: "Psst!"
(Terry Pratchett, Small Gods)