Paragraph 16 of The Dogmatic Constitution on the Church (Lumen gentium)* reads, in part:
[...]But the plan of salvation also includes those who acknowledge the Creator. In the first place amongst these there are the Mohammedans, who, professing to hold the faith of Abraham, along with us adore the one and merciful God, who on the last day will judge mankind.
And I can see the next argument coming: that Vatican II was not "infallible."
Look at the name of the document: it's a DOGMATIC CONSTITUTION. I.E. The Council and the pope were looking to make an authoritative statement on the Catholic Faith.
