Which of the following components can be used to reduce thermal drift in crystal oscillators?

Thermal drift occurs when changes in ambient temperature alter the physical and electrical characteristics of circuit components, which in turn causes the oscillator's resonant frequency to wander. To maintain a stable frequency, the components in the frequency-determining network must resist these temperature changes. NP0 (Negative-Positive-Zero) capacitors, also known as C0G capacitors, are manufactured with specific dielectrics designed to have a temperature coefficient of essentially zero. This means their capacitance remains extremely stable regardless of how hot or cold the operating environment gets. Other components listed, such as wirewound resistors or toroidal inductors, do not inherently possess this zero-drift temperature coefficient and are not used specifically to cure thermal drift in crystal oscillators.