When a λ/4 transmission line is used for impedance matching, then which of the following is valid?

• A. standing waves are present on the λ/4 transmission line
• B. no standing waves on the λ/4 transmission line
• C. standing waves are not present both on the feed line and the matching λ/4 line
• D. standing waves are present on both the feed line and the matching λ/4 line