Final answer:
The safest terms to use with Spanish-speakers are nationality-based markers of identity for heritage or ethnic background and referring to the language as Spanish.
Step-by-step explanation:
The safest terms to use with Spanish-speakers are:
a. To refer to heritage or ethnic background: nationality-based markers of identity like “Chicano”, “Mexican-American”, “Tejano” or “Cuban”.
b. To refer to the language: Spanish.