Your recommendation sounds like a question. Here's the fix.

DRAFT for Fred to edit.

Listen to yourself say: “I think we should go with option B?” Now: “I think we should go with option B.” Same words. One sounds like a question, the other like a decision.

When we’re nervous, our pitch rises at the end of sentences. People hear doubt, even when the engineering is solid.

Three exercises

1. Land the last word. Read three lines of an email aloud, dropping your pitch on the final word of each.
2. Name and title. Say your name and job title, landing the last word low. Do it until it feels natural.
3. Record and compare. Record a one-minute explanation of a current project. Listen for the rises, then record it again.

Why it works

Downward inflection is how certainty sounds. You’re not faking confidence. You’re removing a signal that was telling the room you weren’t sure.