Which sentence is written correctly?

a. ms. andrade showed us a documentary in class today because the film “focuses on a similar subject” to a book we are going to read.
b. ms. andrade showed us a documentary in class today because the film, “focuses on a similar subject” to a book we are going to read
c. ms. andrade showed us a documentary in class today because the film “focuses on a similar subject” to a book we are going to read.
d. ms. andrade showed us a documentary in class today because the film, “focuses on a similar subject” to a book we are going to read.

Website: address: 126 wallace avenue, downingtown, pa 19335 ph no: (484) 875-5400 is your child struggling to learn in a classroom environment? if you live in pennsylvania, consider enrolling them in an online school! 21st century cyber charter school is a pennsylvania online school where our students can receive a high-quality education. we pride ourselves on being the best pennsylvania online school because our staff works extremely hard to allow our students to be successful with our curriculum. our curriculum is currently available for students in 6th-12th grade who wish to learn in a new environment. at 21st century cyber charter school, we offer art and physical education kits, calculators, tablets, and internet tracking software. we believe that each of these items will our students focus on becoming the best student they can be. in order to begin the enrollment process at our pennsylvania online school, visit our website to view the dates and requirements.